eppees



(No Model.) 2 Sheets-Sheet 1.

ELEPPERS], PERSPECTIVE DRAWING APPARATUS.

No. 530,477. Patented Dec. 4, 1894.

. INVENTOH WITNESSES:

(No Mbdel.) 2 Sheets-Sheet 2.

H. EPPERS. PERSPECTIVE DRAWING APPARATUS.

No. 530,477. Patented D90.- 4, 1894.

INVENTOH WITNESSES:

UNITED STATES PATENT OFFICE.

HEINRIOH EPPERS, OF BRAUNSOHWEIG, GERMANY, ASSIGNOR TO RUDOLF I SOHWARZ, OF VIENNA, AUSTRIA-HUNGARY.

PERSPECTlVE-DRAWlNG APPARATUS.

SPECIFICATION forming part of Letters Patent No. 530,477, dated December 4, 1894.

Application filed p l ri N ,0 2- (No model.) Patented in Austria-Hungary July 18, 1891, No. 34,185 and No. 59,482; in Germany July 18. 1891,No.66.84=9,and February 10, 1892,1To. 66,541: inFi-anceJuly 25,1891,No.215,112| in Belgium March 26, 1892,No. 98,975, and in England October 6, 1892.110. 17,837.

To wZZ whom it may concern.-

Be it known that I, HEINRICH EPPERS, a subject of the German Emperor, residing at Braunschweig, Germany, have invented cer- 5 tain new and useful Improvements in Perspective-Drawing Apparatus, (for which I have obtained patentsin Germany, No. 65,849 and No. 66,541, dated July 18, 1891, and February 10, 1892, respectively; in England, No.

17,837, dated October 6, 1892; in Belgium, No. 98,975,dated March 26, 1892; in France, No. 215,112, dated July 25,1891, and in Austria- Hungary, No. 345,185 and No. 59,482, dated July.l8,' 1891,) of which the following is a :5 specification.

My invention relates to certain improvements in camera-lucidas and apparatus employed in connection therewith, it being adapted for facilitating the copying of pictures or other near objects and also for delineating copies of landscapes, buildings, 650., all of which are caused to appear on the surface on which the copy is to be drawn.

The objects of the invention are the production of a camera-lucida which is adapted for practical purposes and is simple and inexpensive, as the prism is dispensed with and the high cost of its production thereby'avoided.

A further object is to provide means-for determining whether or not the parts of the device are properly adjusted relatively to each other and also for ascertaining the proportionate size of the projection or'image relatively to the original.

To these ends my invention consists, first, of a plane mirror which is silvered and bared at alternate intervals so that it partly reflects light and partly permits light to pass through it, such mirror being supported in a suitable 4o holder; secondly, of a mirror such as described in combination with an ordinary plane mirror, both being supported in proper relative position to each other Within the holder; thirdly, of a supporting-base for the entire apparatus provided with a parallel series of indicatorlines, and an obj ect-board also provided with a parallel series of indicatorlines and supported above and relatively movable to the supporting-base, all of the indicator lines extending in parallel direction; and lastly, my invention consists of certain other features of construction all of which willbe hereinafter described and then particularly specified in the claims.

In the'accompanying drawings, Figure 1 is a perspective view of the complete device. Fig. 2 is a plan view of the storage-box for the detachable parts, the other parts being shown in folded condition. Fig. 3 is a side view, showing the storage-box in section, and the mirrors arranged in relative position, the holder therefor being omitted, and the mirrors enlarged for the sake of clearn ess. Fig. 4 is an enlarged Ivertical longitudinal section of the mirror- "holder and mirrors on line 4, 4, of Fig. 1.

Fig. 5 is a section on line 5, 5,0f Fig. 4:. Figs. 6 and 7 are respectively plan and transverse sectional views of the lower mirror. Fig. 8 is a side view of the device, the mirror-holder and the auxiliary mirror being omitted, and the main mirror being enlarged, as in Fig. 3, for the sake of clearness. Fig. 9 is a diagram matic view of the obj ect-board and draw ing board, and showing the relative location of the parallel indicator-lines, whereby the proportionate size of the projection relatively to the original may be determined, and Fig. 10 is a side view, showing the apparatus mounted on a tripod and adapted for outdoor use in copying landscapes.

Similar letters and figures of reference indicate corresponding parts. In the drawings letterAdesignates the supporting base or board of the apparatus, the same being in the shape of a receptacle adapted to contain the attachments of the apparatus when they are not in use. Pivoted to one side of the supporting-base A on a threaded pin B is one of three folding bracket-arms, namely arm 0, which arms C, O, O are pivotally connected by means of a threaded pin B and onto these pins B and B are turned the clamping-nuts b, b, so that arms 0 and 0 may be adjusted in different positions on arm 0 by the nut b, and arm 0 5 may be adjusted on the supporting-base, to-

gether with the others, by the nut 12. An object-board D is provided with a threaded pin 61 on one edge, which pin passes through the outer end of adjustable arm 0 so that the board D may be adjusted at various angles of inclination with respect to the supportingbase A (drawing board) by means of the clamping-nut D screwed onto the pin.

The mirror holder presently to be described is removably attached to the arm C, and the same together with the object-board D can therefore be detached from the arms and placed in the box-like supporting-base A, so that the three arms may be folded alongside of said base, as shown in Fig. 2. An elastic band B attached to board D provides means for securing the object thereto.

The mirror-holder, see Figs. 1, 4 and 5 consists of a sheet-metal box-body E which is open at the bottom and at one end and has at one side a projecting wire arm e secured rigidly thereto and formed at its outer end into a spring-clip e. In the upper part of the box E is an eye-hole 6 through which the mirrors in the box may be seen. The mainmirror F,see in addition to those stated, Figs. 6 and 7, is of the plane order and is composed of a flat glass body which is silvered, platinized or otherwise suitably prepared so as to have alternate reflecting and transparent portions. The silvered or reflecting portions are indicated byf, being white in the drawings, and the transparent portions f are black, and the reflecting and transparent parts alternate one with the other in the form of parallel stripes, as shown. An inclined clip G made of bent-up sheet-metal is secured to the box E at a point near the closed end of the same just below the eye-hole e The mirror F is sprung into the clip G so as to be retained therein by friction in inclined position under the eye-hole e with its upper face presented toward the open end of the box E, and its lower face toward the open bottom thereof. On the under side of the top of the box E in front of the eye-hole is arranged a pair of guides g into which is adapted to be slid an auxiliary mirror H, the position of which when in use, it will be seen, is above the mirror F, and at an acute angle thereto.

In using the apparatus for copying pictures the bracket-arm O is raised to the required extent, and then secured in the raised position by tightening the nut b, the bracketarms 0, 0 being then unfolded so as to extend in opposite directions, as shown in Fig. l, in which position they are set by tightening the nut 19'. Before setting the bracket-arms O, 0', O in fixed position the object-board D is first preferably secured on the arm 0 and the spring-clip e of the mirror-holder sprung onto the arm 0, but of course this can be done afterward. When the parts are adjusted in the positions shown in Fig. 3 a positive or upright projection or image is thrown onto the supporting-base A which forms the di'awingboard, the light rays thrown from the picture on the objectboard D being reflected from the mirror 11 and thrown partly onto and partly through the main mirror F, so that on placing the eye to the eye-hole such projection or image and the pencil may be plainly seen and the same may be readily traced upon the paper placed on the drawing-board.

lVhen it is desired to project a negative or reversed picture, the mirror II is dispensed with, as shown in Fig. 8, the mirror F being then placed at such an angle of inclination that it halves the angle between the objectboard D and the supporting-base A, the object-board being adjusted at a right-angle to the base or drawing-board. In like manner as before the mirror F permits the pencil to be seen, together with the projection of the picture, but of course the same is reversed. It is obvious without illustration that instead of mounting the object-board D and the mirror-holder E, e, on the movable bracketarms, the object-board may be mounted on fixed brackets and the mirror-holder mounted directly on a pivoted arm, such as 0. Such a construction is well adapted for projecting pictures, but the construction shown herein is especially adapted for projecting landscapes and small objects, as well as pictures. When it is to be used for projecting landscapes, the camera lucida is preferably mounted on a tripod or other suitable stand T, see Fig. 10, and the arm C may be used as a brace against which to rest the shoulder. When the distance from the object to the camera is equal to the distance from the camera to the drawing-board it will be understood that the projection will be of natural size, and that accordingly as the distances are altered the projection will be either an enlargement or a reduction of the original object. Now in order to determine as to the proper or improper adjustment of the parts of the apparatus relatively to one another, and also to ascertain the proportionate size of the projection to the original, I provide means such as shown more particularly in Fig. 9, wherein M indicates the objectboard and N indicates the drawing-board, both being shown of the same size. The media for such purpose consist of a number of parallel indicator lines, or sets of lines. on the obj ect-board the set being marked 3, 2, 1, 2, 3 and the other set, on the drawing-board, being marked III, II, I, II, III. The central lines 1 on board M and I on board N are when the apparatus is set up directly in line with the eye-hole e Lines 2, 2 and 3, 3, respectivelyare equidistant from the center line 1 on M and so are lines II, II, and III, III, equidistant from center line I on N, lines 3 and III being also equidistant relatively to each other from the center. The distance of lines 2, 2, from their central line 1 is arranged at two-thirds of the distance of lines II, II from their central line I. When, therefore the apparatus is properly set up, the eye of the observer should see the center line 1 and I as true continuations of each other, and when the distances between the camera and object and camera and projection are equal, then the lines 3, 3, should appear astrue continuations of lines III, III, in which case the projection will be the natural size of the original. When on the other hand lines 2, 2, appear as true continuations of lines III, III, then the distance between the camera and original is three times less than the distance between the camera and projection, and the original must therefore be just three times larger than the projection. In projecting landscapes and large objects, the lines of perpendicular objects such for instance as buildings should be parallel with the lines on the drawing-board.

Having thus described my invention, I claim as new and desire to secure by Letters Patent 1. In combination with a mirror-holder provided with an eye -hole, a plane mirror adapted to be arranged therein, and bared at intervals, so that parts reflect and parts transmit light, substantially as set forth.

v2. In combination with a mirror-holder provided with an eye-hole, a plane mirror adapted to be arranged therein, and bared at intervals, so that parts reflect and parts transmit light, and an auxiliary plane mirror adapted to be arranged above the first mirror, substantially as set forth.

3. A mirror-holder, consisting of a box open at the bottom and one end and having an eyehole, means for holding two mirrors therein, and an arm extending from the box and provided with a spring-clip, substantially as set forth.

4. In combination with a supporting-base or drawing-board, and folding-bracket-arms ing transversely through one end of the arm and through one side of the supporting-base or drawing-board, two auxiliary arms, and a pivot passing transversely through the inner ends of the auxiliary arms and the other end of the supporting-arm, said arms being adapted to fold together alongside of the base, of a detachable object-board and-a detachable mirror-holder applied to the outer ends of the auxiliary arms when the same are spread, substantially as set forth.

5. In combination with a snpporting base or drawing-board provided with parallel indicator-lines, and an obj ect-board also provided with parallel indicator-lines adapted to register with the aforesaid indicator-lines, those two indicator-lines on the object-board nearest the central line thereof being nearer the same than the corresponding lines of the drawing-board are nea'rer their central line,

a mirror, and means for supporting the object-board and mirror in triangular relation to the supporting-base, substantially as set forth.

In testimony that I claim the foregoing as my invention I have signed my name in presence of two subscribing witnesses.

HEINRICH EPPERS.

Witnesses:

JULIUS SEoKEL, GEO. R. TINGLE, Jr.

comprising a supporting-arm, a pivot pass- 

